Scaling and annealing of metal articles.



TED STATES PATENT OFFICE.

FRANK PERRY, OF TIPTON, ENGLAND, ASSIGNOR T0 METALLOIDS LIMITED, OFTIFTON, ENGLAND.

SCALING AND ANNEALING OF METAL ARTICLES.

No Drawing.

To all whom it may concern:

Be it known that I, FRANK PERRY, a subject of the King of Great Britainand Ire- I land, residing at Tibbinsgton Works, Tipin annealing metalarticles or reducing or preventing the formation of non-metallicsurfaces such as coatings of oxid on such articles when subjected to theheat of a muflle or the like.

In processes previously proposed various constituentshave been removedfrom the reducing gas, such as water vapor, sulfur compoundsandunsaturated hydrocarbons, but none of these has been entirelyefi'ective in preventing the formation of film like deposits ofnon-metallic substances on the surfaces of the articles while in thechamber.

The present invention consists in removing the saturated hydrocarbonssuch as methane in addition to such deleterious constituents as excesswater vapor, sulfur compounds and unsaturated hydrocarbons all theseconstituents being removed before the gas enters the mutlle.

In one convenient manner of carrying the invention into effect, the gasbefore it enters the muflle and after it has been treated for theremoval of water vapor, sulfur compounds and unsaturated hydrocarbons ifthese are present, is passed through a hot chamber containing loosepieces of iron, or through a hot iron tube, the iron serving to combinewith and consequently remove those constituents which are harmful to theiron or other metal articles to be treated. I find the most advantageoustemperature for the iron is about 250 0., and I operate, therefore, ator near this temperature. If

.the iron is excessively heated it no longer removes the methane.Passing producer gas through an iron tube for the removal ofSpecification of Letters Patent.

Patented Apr. 2, 1918.

Application filed February 15, 1917. Serial No. 148,873.

sulfur compounds has been proposed, but the temperature necessary is toohigh to make the removal of methane or other saturated hydrocarbonspossible.

Periodically when the iron becomes coated with deposits from the gas itis replaced by fresh material.

By this invention perfectly clean metal surfaces can be produced orpreserved in an nealing' operations in a simple and inexpensive manner,

The invention is not limited to any particular means for removing thesaturated hydrocarbons, and the removal of the other constituents formsper se no part of the invention.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is 1. A process of annealing metal articles,which consists in introducing into the oven containing the articles,Mond gas purified by removing the saturated hydrocarbons such as methanein addition to such deleterious constituents as excess water vapor,sulfur compounds, and unsaturated hydro carbons.

2. A process of annealing metal articles, which consists in introducinginto the mufile containing the articles, Mond gas first purified byremoving therefrom sulfur compounds, water vapor and unsaturatedhydrocarbons and passing such urified gas prior to its entrance to themu e containing the metal articles over iron at a temperature about 2500., substantially as described.

3. A process .of annealing metal articles which consists in introducinginto the mufile containing the articles, Mond gas first purified byremoving therefrom sulfur compounds, water vapor and unsaturated,hydrocarbons and then passing the purified gas through an iron tube at atemperature of about 250 C., prior to entrance to the mufile,substantially as described.

In testimony whereof I have signed my name to this specification.

FRANK PERRY.

